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<div class="titlepage"><div><div><h4 class="title">
<a name="beast.ref.boost__beast__detect_ssl"></a><a class="link" href="boost__beast__detect_ssl.html" title="detect_ssl">detect_ssl</a>
</h4></div></div></div>
<p>
        <a class="indexterm" name="idm44861250541616"></a>
      </p>
<p>
        Detect a TLS client handshake on a stream.
      </p>
<h5>
<a name="beast.ref.boost__beast__detect_ssl.h0"></a>
        <span class="phrase"><a name="beast.ref.boost__beast__detect_ssl.synopsis"></a></span><a class="link" href="boost__beast__detect_ssl.html#beast.ref.boost__beast__detect_ssl.synopsis">Synopsis</a>
      </h5>
<p>
        Defined in header <code class="literal">&lt;<a href="../../../../../../boost/beast/core/detect_ssl.hpp" target="_top">boost/beast/core/detect_ssl.hpp</a>&gt;</code>
      </p>
<pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">class</span> <a href="../../../../../../doc/html/boost_asio/reference/SyncReadStream.html" target="_top"><span class="emphasis"><em>SyncReadStream</em></span></a><span class="special">,</span>
    <span class="keyword">class</span> <a class="link" href="../concepts/DynamicBuffer.html" title="DynamicBuffer"><span class="emphasis"><em>DynamicBuffer</em></span></a><span class="special">&gt;</span>
<span class="keyword">bool</span>
<span class="identifier">detect_ssl</span><span class="special">(</span>
    <span class="identifier">SyncReadStream</span><span class="special">&amp;</span> <span class="identifier">stream</span><span class="special">,</span>
    <span class="identifier">DynamicBuffer</span><span class="special">&amp;</span> <span class="identifier">buffer</span><span class="special">,</span>
    <span class="identifier">error_code</span><span class="special">&amp;</span> <span class="identifier">ec</span><span class="special">);</span>
</pre>
<h5>
<a name="beast.ref.boost__beast__detect_ssl.h1"></a>
        <span class="phrase"><a name="beast.ref.boost__beast__detect_ssl.description"></a></span><a class="link" href="boost__beast__detect_ssl.html#beast.ref.boost__beast__detect_ssl.description">Description</a>
      </h5>
<p>
        This function reads from a stream to determine if a client handshake message
        is being received. The call blocks until one of the following is true:
      </p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
            A TLS client opening handshake is detected,
          </li>
<li class="listitem">
            The received data is invalid for a TLS client handshake, or
          </li>
<li class="listitem">
            An error occurs.
          </li>
</ul></div>
<p>
        The algorithm, known as a <span class="emphasis"><em>composed operation</em></span>, is implemented
        in terms of calls to the next layer's <code class="computeroutput"><span class="identifier">read_some</span></code>
        function. Bytes read from the stream will be stored in the passed dynamic
        buffer, which may be used to perform the TLS handshake if the detector returns
        true, or be otherwise consumed by the caller based on the expected protocol.
      </p>
<h5>
<a name="beast.ref.boost__beast__detect_ssl.h2"></a>
        <span class="phrase"><a name="beast.ref.boost__beast__detect_ssl.parameters"></a></span><a class="link" href="boost__beast__detect_ssl.html#beast.ref.boost__beast__detect_ssl.parameters">Parameters</a>
      </h5>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead><tr>
<th>
                <p>
                  Name
                </p>
              </th>
<th>
                <p>
                  Description
                </p>
              </th>
</tr></thead>
<tbody>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">stream</span></code>
                </p>
              </td>
<td>
                <p>
                  The stream to read from. This type must meet the requirements of
                  <span class="emphasis"><em>SyncReadStream</em></span>.
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">buffer</span></code>
                </p>
              </td>
<td>
                <p>
                  The dynamic buffer to use. This type must meet the requirements
                  of <span class="emphasis"><em>DynamicBuffer</em></span>.
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">ec</span></code>
                </p>
              </td>
<td>
                <p>
                  Set to the error if any occurred.
                </p>
              </td>
</tr>
</tbody>
</table></div>
<h5>
<a name="beast.ref.boost__beast__detect_ssl.h3"></a>
        <span class="phrase"><a name="beast.ref.boost__beast__detect_ssl.return_value"></a></span><a class="link" href="boost__beast__detect_ssl.html#beast.ref.boost__beast__detect_ssl.return_value">Return
        Value</a>
      </h5>
<p>
        <code class="computeroutput"><span class="keyword">true</span></code> if the buffer contains
        a TLS client handshake and no error occurred, otherwise <code class="computeroutput"><span class="keyword">false</span></code>.
      </p>
</div>
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      Falco<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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